TMC2160 DATASHEET (Rev. 1.02 / 2018-NOV-19)
15
Attention
In case VSA is supplied by a different voltage source, make sure that VSA does not drop out during
motor operation. Stop and disable the motor before VSA power down. This is not necessary, when
VSA voltage is derived from VS supply, as both supplies go down in parallel in this case.
3.2 External Gate Voltage Regulator
At high supply voltages like 48V, the internal gate voltage regulator and the internal 5V regulator
have considerable power dissipation, especially with high MOSFET gate charges, high chopper
frequency or high system clock frequency >12MHz. A good thermal coupling of the heat slug to the
system PCB GND plane is required to dissipate heat. Still, the thermal thresholds will be lowered
significantly by self-heating. To reduce power dissipation, supply an external gate driver voltage to the
TMC2160. Figure 3.2 shows the required connection. The internal gate voltage regulator becomes
disabled in this constellation. 12V +/-1V are recommended for best results.
12V Gate Voltage
+VG
VSA
12VOUT
5VOUT
11.5V Voltage
regulator
2.2µ
5V Voltage
regulator
2.2µ
2R2
VCC
470n
Figure 3.2 External gate voltage supply
Hint
With MOSFETs above 50nC of total gate charge, chopper frequency >40kHz, or at clock frequency
>12MHz, it is recommended to use a VSA supply not higher than 40V.
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